Need to run a lawn sprinkler valve (24 volts AC) from a 12 volt DC power supply. Any ideas?
(1) Why? (2) Get out a variable DC supply and gradually crank up the voltage until the valve actuates, then go up maybe 10-20%. Most likely that DC voltage (VV) will be less than 12V. Measure the current consumed (I). Add a series resistor between 12V supply and valve terminal of value (12-VV)/I. Make sure power rating is adequate. ...Jim Thompson